Some videos won't play

I just tried to play the videos in Steve Wright's article entitled, "Invisible Effects", and none of them would play. I can play other internet videos from Cow but not some. Also, I cannot play some of the videos on the Digital Juice website. Some will play but some will not. I just do not understand why.

I have installed the latest Windows updates and as far as I know the latest Quicktime, Flash and Windows Media player but can some one steer me in the right direction on this irritating problem? Please.

I would guess you don't have the latest version of quicktime. The movies in the article there is a direct link to a mov file. The quicktime plug-in in your browser should take over and play it there. If not you probably have a problem with your quicktime browser plug-in. Try re-updating quicktime:

Abraham, thank you for your response but its still not working. I went to Apple for the latest Quicktime download and downloaded it but during installation it only offered two choices.
1, fix
2, uninstall

I chose fix and it ran ok but when I tried to play the Invisible Effects video it wouldn't play. Instead, I get the yellow triangle with the exclamation point in the lower left of my window. It also say, "error on the page".

I have Quicktime 7.5.5 installed and other Quicktime files play, but not all.